Energy damping estimation in automotive magneto-rheological elastomers through finite element method

2018 ◽  
Vol 1 (1) ◽  
pp. 292-300 ◽  
Author(s):  
Isa Banagar ◽  
Hamed Saeidi Googarchin
Keyword(s):  
Smart Materials ◽  
Potential Field ◽  
Mechanical Load ◽  
Applied Potential ◽  
Precise Calculation ◽  
Flux Intensity ◽  
Vehicle Production ◽  
Magneto Rheological ◽  
Energy Absorbing ◽  
Damping Estimation

Magneto-rheological elastomers (MRE), which undergo upon the smart materials, are one of the very common products frequently used in modern vehicle production nowadays. For their visco-hyper properties, elastomers find a prevalent use as an energy absorber. Inducing a magnetic field would make their energy absorbing characteristics vary upon the desired ones by adjusting the applied potential field. A precise calculation of the amount of their absorption with respect to the potential field has a key role in the prediction of MREs’ responses. Therefore, in this study, a hyper-visco-magnetic constitutive model is utilized in COMSOL commercial software for the energy damping estimation in magneto-rheological elastomers. A representative volume element has been considered for the calculation of hysteresis loop areas as a characteristic of energy damping behaviour in MREs. Finally, the effects of magnetic flux intensity and mechanical load frequency in the energy damping behaviour of automotive magneto-rheological elastomers are evaluated.

scholarly journals Investigation on the Mechanical Properties of MRE Compounds

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Testing Machine ◽  
Static Test ◽  
Vibration Isolators ◽  
Elastomeric Matrix ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Rheological Effect

This paper describes an experimental investigation conducted on magneto-rheological elastomers (MREs) with the aim of adopting these materials to make mounts to be used as vibration isolators. These materials, consisting of an elastomeric matrix containing ferromagnetic particles, are considered to be smart materials, as it is possible to control their mechanical properties by means of an applied magnetic field. In the first part of the paper, the criteria adopted to define the characteristics of the material and the experimental procedures for making samples are described. The samples are subjected to a compressive static test and are then, adopting a testing machine specially configured, tested for shear periodic loads, each characterized by a different constant compressive preload. The testing machine is equipped with a coil, with which it is possible to vary the intensity of the magnetic field crossing the sample during testing to evaluate the magneto-rheological effect on the materials’ characteristics in terms of stiffness and damping.

MRE Damping Characteristics Evaluation

2016 ◽  
Vol 699 ◽  
pp. 31-36 ◽  
Author(s):  
Eduard Chirila ◽  
Ionel Chirica ◽  
Doina Boazu ◽  
Elena Felicia Beznea
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Smart Materials ◽  
Magnetorheological Elastomers ◽  
Damping Characteristics ◽  
The Subject ◽  
Energy Absorbing ◽  
The Magnetic Field ◽  
Material Form

The paper addresses the study of the damping characteristics estimation and behaviour of the magnetorheological elastomers (MREs) in the absence of magnetic field. This type of material actively changes the size, internal structure and viscoelastic characteristics under the external influences. These particular composite materials whose characteristics can vary in the presence of a magnetic fields are known as smart materials. The feature which causes the variation of properties in magnetic fields is explained by the existence of polarized particles which change the material form by energy absorbing. Damping is a special characteristic that influences the vibratory of the mechanical system. As an effect of this property is the reducing of the vibration amplitudes by dissipating the energy stored during the vibratory moving. The main characteristic that is based on the determination of the damping coefficient is the energy loss, which is the subject of the present paper. Before to start the characteristics determination in the presence of the magnetic field, it is necessary to study these characteristics in the absence of magnetic field. The MRE specimens have been manufactured and tested under the light conditions (non magnetic field). A special experimental test rig was built to investigate the response of the MRE specimens under the charging force. The experimental results show that the loss energy of the MRE specimen can be determined from the charging-discharging curves versus displacement. The results of the MRE specimen are presented in this paper: MRE with feromagnetic particles not exposed in magnetic field during fabrication.

Analysis of Magneto Rheological Fluid Journal Bearing

2019 ◽  
Vol 895 ◽  
pp. 152-157 ◽  
Author(s):  
B. Narasimha Rao ◽  
A. Seshadri Sekhar
Keyword(s):  
Magnetic Field ◽  
Newtonian Fluid ◽  
Carrying Capacity ◽  
Smart Materials ◽  
Journal Bearing ◽  
Fluid Film ◽  
Load Carrying Capacity ◽  
Mr Fluid ◽  
Load Carrying ◽  
Magneto Rheological

Magneto Rheological (MR) fluids are a class of smart materials where the shear stress is not directly proportional to rate of shear. The viscosity of fluid changes as magnetic field changes and hence this phenomenon is very useful in bearing-rotor system for attenuating the vibrations. In the present study the application of MR fluid as lubricant instead of Newtonian fluid in the journal bearing is explored through steady state, dynamic characteristics and stability. MR fluid film has been modeled as per Bingham rheological model. FEM with three node triangular elements has been used to solve the Reynolds equation both for the Newtonian fluid film and MR fluid film. The results show the load carrying capacity in the case of MR fluid journal bearing is higher than that of using the Newtonian fluid. The load carrying capacity increases with the increasing magnetic field for all eccentricity ratios. The results also show better stability of the bearing using MR fluid at higher eccentricity ratios. The unbalance response of the rotor mounted on the journal bearing using MR fluid is also estimated to be lower than that of with the Newtonian fluid.

Mesoscale Analysis of Porous Shape Memory Alloys

2000 ◽  
Author(s):  
Virginia G. DeGiorgi ◽  
Muhammad A. Qidwai
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Dynamic Loading ◽  
Smart Materials ◽  
Bulk Material ◽  
Material Behavior ◽  
Loading Conditions ◽  
Shape Variation ◽  
Energy Absorbing ◽  
Dynamic Loading Conditions

Abstract Shape memory alloys are frequently used in smart materials and structures as the active component. Their ability to provide high force and large displacements has been used to the advantage in many applications. The majority of applications to date utilize solid shape memory alloy materials in quasi-static loading conditions. Recent work has proposed the use of porous SMAs as an energy absorbing material under dynamic loading conditions. The use of porous SMAs under dynamic loading will require advancements in the understanding of SMA behavior both in the dense or solid form and in the porous form. The current work examines the quasi-static behavior of porous SMA as a first step. The material behavior is modeled on a mesoscale level allowing for the examination of pore size and shape variation effects. Bulk material response is estimated and compared with micromechanical periodic unit cell predictions.

Improving Vehicle Performance and Operator Ergonomics: Commercial Application of Smart Materials and Systems

2011 ◽  
Author(s):  
Douglas Ivers ◽  
Douglas LeRoy
Keyword(s):  
Smart Materials ◽  
Mr Damper ◽  
Electrical Current ◽  
Step Response ◽  
Commercial Application ◽  
Material Technology ◽  
Mr Fluid ◽  
Mr Dampers ◽  
Magneto Rheological ◽  
Scale Step

This paper will discuss how controllable material technology, such as the use of active magneto-rheological (MR) dampers, improves vehicle primary and secondary suspensions. Although relatively new to the marketplace, semi-active suspensions in commercial automobiles and off-highway vehicles have been proven through the use of active MR dampers since 1998. In fact, MR suspension dampers are found today on the commercial vehicles of an increasing number of automotive OEMs and leading off-highway OEMs. MR fluid dampers are simple in design and have the advantage of no moving parts. The resistive force from an MR damper is generated as iron particles, suspended in the magneto-rheological fluid (MR fluid); pass through a magnetic field controlled by the electrical current passing through an electric coil contained within a moving piston surrounded by fluid. By adjusting the current to the damper coil in response to feedback from vehicle sensors and a controller, the damping response of the suspension can be optimized and controlled in real time to provide optimal operator comfort. The MR Damper System has a full-scale step response of less than 10 milliseconds. Sophisticated control algorithms adapt to large changes in payload, enabling the vehicle to meet ride metrics without pneumatic load leveling. Other benefits of the MR damping system include higher speed in NATO double-lane change tests, reduced risk of roll-over, improved accuracy of mounted weapons, and improved vehicle durability and readiness.

scholarly journals Magneto-Rheological Elastomer Composites. A Review

2020 ◽  
Vol 10 (14) ◽  
pp. 4899 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Lorenzo Abate ◽  
Ignazio Blanco
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Mechanical Response ◽  
Viscoelastic Behavior ◽  
Shear Mode ◽  
Dynamic Shear ◽  
Elastomeric Matrix ◽  
Elastomer Composites ◽  
Magneto Rheological ◽  
Micro Structures

Magneto-rheological elastomer (MRE) composites belong to the category of smart materials whose mechanical properties can be governed by an external magnetic field. This behavior makes MRE composites largely used in the areas of vibration dampers and absorbers in mechanical systems. MRE composites are conventionally constituted by an elastomeric matrix with embedded filler particles. The aim of this review is to present the most outstanding advances on the rheological performances of MRE composites. Their distribution, arrangement, wettability within an elastomer matrix, and their contribution towards the performance of mechanical response when subjected to a magnetic field are evaluated. Particular attention is devoted to the understanding of their internal micro-structures, filler–filler adhesion, filler–matrix adhesion, and viscoelastic behavior of the MRE composite under static (valve), compressive (squeeze), and dynamic (shear) mode.

A state of art on magneto-rheological materials and their potential applications

2018 ◽  
Vol 29 (10) ◽  
pp. 2051-2095 ◽  
Author(s):  
Raju Ahamed ◽  
Seung-Bok Choi ◽  
Md Meftahul Ferdaus
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Wide Spectrum ◽  
Materials Modeling ◽  
Different Types ◽  
Potential Applications ◽  
Magneto Rheological ◽  
Designed Materials ◽  
External Stimuli ◽  
The Magnetic Field

Smart materials are kinds of designed materials whose properties are controllable with the application of external stimuli such as the magnetic field, electric field, stress, and heat. Smart materials whose rheological properties are controlled by externally applied magnetic field are known as magneto-rheological materials. Magneto-rheological materials actively used for engineering applications include fluids, foams, grease, elastomers, and plastomers. In the last two decades, magneto-rheological materials have gained great attention of researchers significantly because of their salient controllable properties and potential applications to various fields such as automotive industry, civil environment, and military sector. This article offers a recent progressive review on the magneto-rheological materials technology, especially focusing on numerous application devices and systems utilizing magneto-rheological materials. Conceivable limitations, challenges, and comparable advantages of applying these magneto-rheological materials in various sectors are analyzed critically, which provides a clear pathway to the researchers in selecting and utilizing these materials. The review starts with an introduction to the elementary description of magneto-rheological materials and their significant contribution in various fields. Following this, different types of the magneto-rheological materials, modeling of the magneto-rheological materials, magneto-rheological material–based devices, and their applications have been extensively reviewed to promote practical use of magneto-rheological materials in a wide spectrum of the application from the automobile to medical device.

Investigation of Locking Force of Stay Cable Vibration Control Using Magneto-Rheological Fluid Damper

Aerospace ◽  
2006 ◽  
Author(s):  
Liu Min ◽  
Vineet Sethi ◽  
Gangbing Song ◽  
Hui Li
Keyword(s):  
Vibration Control ◽  
Smart Materials ◽  
Mr Damper ◽  
Pole Placement ◽  
Stay Cable ◽  
Cable Vibration ◽  
Bridge Model ◽  
Mode Vibration ◽  
Magneto Rheological ◽  
Multi Mode

This paper analyzes the locking force of a stay cable equipped with a Magneto-rheological (MR) damper. For the single mode vibration of the stay cable, the formula of the locking force is derived and the important factors that affect the locking force are analyzed. The experimental investigations of the locking force of the stay cable vibration control are carried out on a cable-stayed bridge model equipped with an MR damper to verify of the computational locking force in the Smart Materials and Structures Laboratory at University of Houston. For the multi-mode vibration of the stay cable, the modal shapes of the stay cable vibration are estimated by utilizing a pole placement observer using the acceleration values at selected locations of the stay cable and the locking forces of the stay cable in multi-mode vibration are numerically obtained. In all experimental cases, the locking forces based on the analytical and numerical formulas approximately match the experimental results.

Dynamic Analysis of a Smart Base-Isolation System Based on MR Elastomers

2010 ◽  
Author(s):  
Hyung-Jo Jung ◽  
Jeong-Su Park ◽  
Jeong-Hoi Koo
Keyword(s):  
Smart Materials ◽  
Base Isolation ◽  
Dynamic Performance ◽  
Building Structure ◽  
Seismic Excitations ◽  
Isolation System ◽  
Base Isolation System ◽  
Magneto Rheological ◽  
Shear Building ◽  
Smart Base Isolation

This paper presents a numerical investigation of a smart base isolation system employing magneto-rheological (MR) elastomers or an MR elastomer-based base isolation system. MR elastomers are a new class of smart materials whose elastic modulus or stiffness can be adjusted depending on the magnitude of the applied magnetic field. Hence, they can be used as controllable stiffness elements in engineering systems. The primary goal of this study is to investigate the dynamic performance of the smart base-isolation in mitigating excessive vibrations of a building structure under earthquake loadings. To this end, a five-story shear building model coupled with a smart base-isolation is developed. Using this model, a series of numerical simulations is performed to evaluate the effectiveness of the MR elastomer-based base isolation system under several historic seismic excitations. The results show that the proposed base isolation system outperform the conventional passive-type base isolation system in reducing the responses of the building structure for all seismic excitations considered in this study.

Investigation on the Dynamic Shearing Characteristics of Magnetic Responsive Gel

2011 ◽  
Author(s):  
Katsuaki Sunakoda ◽  
Naoki Yamamoto ◽  
Hiroshi Nasuno ◽  
Hirohisa Sakurai
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
Storage Modulus ◽  
Smart Materials ◽  
Loss Modulus ◽  
Active Vibration Control ◽  
Hysteresis Loops ◽  
Active Vibration ◽  
Magneto Rheological ◽  
Dynamic Shearing

Material which would be largely changed its physical properties such as storage modulus and loss modulus under magnetic field has a potential of application on industrial fields. Magneto-rheological (MR) fluid has been widely studied since its viscosity is changed under magnetic field, but it is restricted for application of the industrial fields as it has liquid nature. Authors are proceeding with the development of magnetic responsive gels which contain the magnetic responsive particles in consideration of their prior studies. Three kinds of magnetic gels are selected and dynamic shearing characteristics are examined. Storage modulus and loss modulus are obtained under different dynamic frequencies and different magnetic fluxes. Some physical properties such as storage modulus and loss modulus are largely changed by applying magnetic field. The developed gels have an effect of energy dissipation, judging from hysteresis loops of stress-strain. And these smart materials have a potential of semi active vibration control materials.

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